Switch construction with arming means



Nov. 17, 1970 y G. M. FARRELL 3,541,279

swITcH CONSTRUCTION WITH ARMING MEANS Filed sept. 2e, 1968 /NVENTOR GuZfZTr United States Patent O U.S. Cl. 200--6L45 5 Claims ABSTRACT OF THEDISCLOSURE A switch construction having terminal elements with awire-like contact extending between the terminal elements. An opening isdefined by the construction housing for receiving a pin which engagesthe wire-like contact to hold the contact out of engagement with aterminal element. The pin is removable when subjected to a pulling forcewhereby the wire-like contact will be moved into engagement withrespective terminal elements.

The invention also contemplates a novel disturb switch constructionpreferably employed in conjunction with the switch construction referredto. The disturb switch has end terminals which engage terminal elementsof the other switch construction. The disturb switch includes a coilspring located in spaced-apart relationship relative to a conductiveouter wall. A weight is located in the interior of the coil spring sothat the application of physical force, for example if the disturbswitch is kicked or dropped, will complete contact betwen the endterminals.

This invention relates to an improved switch construction, particularlydesigned for military use.

The use of electrical personnel detecting means has previously beensuggested. 'In one detecting system, a plurality of small transmittersare scattered over an area, and when a relatively large body ofpersonnel enter the area, several of the transmitters will be actuatedand signals will be sent to a detecting station. Individuals at thedetecting station can determine from the frequency of the signalswhether the force is large or small. By providing receiving stations atdillerent locations, the individuals receiving the signals can alsopinpoint the location of the personnel.

Since a system of the type described requires the use of a very largenumber of mechanisms, it is desirable to provide as much economy aspossible in their production. Thus, 'the mechanisms should be as simpleas pos.- sible to simplify assembly and to hold down material cost.Furthermore, the operation of the devices should be relatively basic sothat the devices can be located without undue elfort.

It is a general object of this invention to provide improved switchmeans which are particularly suitable for use in conjunction withdetecting means for determining the presence of personnel.

It is a more specic object of this invention to provide switch meansofthe type described which can be economically manufactured and whichare characterized by relatively simple operation.

These and other objects of this invention will appear hereinafter, andfor purposes of illustration, but not of limitation, specilicembodimentsof the invention are shown in the accompanying drawings wherein:

FIG. 1 is a vertical sectional view of a switch constructioncharacterized by the features of this invention;

FIG. 2 is a horizontal sectional view taken about the line 2--2 of FIG.1;

FIG. 3 is a horizontal sectional view taken about the ICC line 3--3 ofFIG. 1 and also including a disturb switch construction characterized bythe features of this invention;

FIG. 4 is a horizontal sectional View of the disturb switch shown inFIG. 3; and

FIG. 5 is a perspective view of a pin structure utilized in the switchshown in FIG. 1.

The switch construction of this invention generally comprisesspaced-apart terminal elements having a spring contact normally urgedinto contacting relationship with said elements. The constructiondefines an opening for receiving a pull out pin which, when insertedinto the opening, will engage the spring contact and force the contactout of contacting relationship with at least one of the terminalelements. The pull out pin is designed so that quick removal willimmediately restore contact to complete a circuit between the terminalelements.

The construction is designed to receive a disturb switch which isprovided with terminals engaging terminal elements of the main switch.When the pull out pin is removed, the construction is armed so that theapplication of physical forces will operate the disturb switch toachieve a signal or to otherwise operate in an electrical circuit.

The disturb switch construction, which has separate utility, preferablycomprises a coil spring extending between opposed supports. One of thesupports includes a terminal in contacting relationship with the spirng.A conductive means is located in surrounding relationship relative tothe spring, and a second terminal is connected to this conductive means.A weight is located within the confines of the coil spring, and theapplication of outside forces will cause movement of the weight andcorresponding movements of the spring whereby the spring will engage thesurrounding conductive member to complete a circuit between theterminals.

The switch construction 10 shown in the drawings comprises an outer capmember 12 deiining a cylindrical side wall 14. An inner cylindrical wall16 is supported on a base 18, and the rim 20 of the cap member engagesthe shoulder 22 defined by the base. An adhesive or other suitable meansmay be employed for securing these pieces together.

The inner cylinder 16 includes a transversely extending supporting wall24. This supporting wall is located in spaced-apart relationshiprelative to the disc 26 which is secured to the top wall 28 of the capmember. p A pair of terminal elements 30 and 32 extend through openings34 defined in the base 18. The upper ends 36 and 38 of these terminalelements extend through openings 40 defined by the supporting wall 24.

As best shown in FIG. 2, a spring contact 42 is located in the spacebetween the supporting wall 24 and the disc 26. The spring contactdefines ends 44 and 46 which normally bear against the ends 36 and 38 ofthe terminal elements. The spring contact curves around a post 48 whichis formed on the supporting wall 24.

The top wall 28 de'lines an opening 50 which is centrally locatedrelative to the construction. A pin 52 is adapted to be inserted intothis opening, and through an axially aligned opening `54 dened by thesupporting wall 24. The central portion of the supporting wall includesa raised section 56 which serves to deline a portion of the opening 54,and which also serves as a spacing means for the center of thesupporting wall.

The pin 52 (FIG. 5) delines a pointed end 53 which engages a post 55extending upwardly from the base 18 to limit entry of the pin.

When the pin 52 is in place, the central portion 58 of the springcontact 42 will be forced outwardly as shown in FIG. 2. This will causethe end l46 of the Contact to pull away from the end 38 of the terminalelement thereby breaking contact between the terminal elements.

-In the preferred form of the invention, the pin 52 is pressed into theopenings 50 and y54 so that a relatively great force is required to pullthe pin out. This arrangement is desired since the switch is consideredto be armed when the pin has been removed, and the switch should bedesigned so that this armed condition will not occur accidentally duringhandling.

As shown in FIG. 3, the open interior of the switch construction will beprovided with a second switch 60. The switch y60 comprises a disturbswitch consisting of a conductive outer casing 162 having a terminal tab64 formed at one end. The opposite end 66 of the casing is beaded forattachment to the flange 68 of insulating member 70. A second terminal72 comprises an extension of the T-shaped element 74 which terminates onthe opposite side of the insulating member. The head of the member 74engages the end of a coil spring 76 with the other end of the coilspring being held by insulating member 718. A steel ball 80 is locatedwithin the open interior of the coil spring. i

The coil spring is designed so that, at a position of rest, the springwill be maintained in spaced-apart relationship relative to thesurrounding conductive wall 62. The freely movable steel ball will,however, result in movement of the coil spring when outside physicalforces result in movement of the switch. For example, if the switch islying on the ground and is kicked by a person walking over the ground,violet movement of the steel ball will occur resulting in contact of thespring with the wall 62.

In a modified form of the invention, the ball 80y can be eliminated. Insuch case, the characteristics of the spring 76 must be such that themass of the spring will be suicient to result in contact with the wall62 when the switch is disturbed. A spring material which is relativelyheavy and of relatively soft temper may be selected for thisapplication.

With or without the use of a weight within the confines of the spring,the arrangement described provides advanta-ges over previously employeddisturb switches. Thus, the instant invention calls for the connectionof the ends of the coil spring to the members 74 and 78 so that thespring is, in effect, suspended between these members. In priorarrangements, coil springs have been employed; however, these priorarrangements provided for connection of the coil spring at only onelend. The free end of the coil spring would provide contact when theswitch was disturbed because of the movement of the free end. Thesearrangements require extremely careful selection of the springs sincethe free end of the springs had to be maintained out of contact with thesurrounding Wall irrespective of the position of the switch housing.With the arrangement of this invention, confining of the coil spring atboth ends provides much broader selectivity from the standpoint ofspring selection.

In a typical application for the illustrated arrangement, the terminalelements 30 and 32 would be attached to a transmitter. The terminalelements l82 `and 84, which are in contact with the disturb switch,would also be connected to the transmitter. It will be appreciated thatwhile the pin 52 is in place, movements imparted to the constructionwill not operate the transmitter since the contact arm 46 will be out ofengagement with the terminal element 38. Similarly, when the pin isremoved and when the construction is at rest, the disturb switch will beopen so that transmission will not occur.

It will be understood that various changes and modications may be madein the constructions described 'which provide the characteristics ofthis invention without departing from the spirit thereof particularly asdened in the following claims.

That which is claimed is:

1. A switch construction comprising spaced-apart terminal elements, aspring contact having portions thereof normally urged into contactingrelationship with said terminal elements, a switch housing including atransversely extending support member and a wall portion in spacedapartrelationship relative to said support member, said spring Contactcomprising a wire-like element confined between said support member andsaid Wall portion, at least one portion of said spring contact beingmovable laterally over the surface of said support member, an openingdened by said wall portion and another opening defined by said supportmember, a pull out pin movable longitudinally relative to saidtransversely extending support member for insertion into said openings,said pull out pin extending into engagement with said spring contact forforcing said one portion of said spring contact out of contactingrelationship with at least one of said terminal elements, and whereinsaid spring contact is restored to contacting relationship with saidterminal elements upon removal of said pull out pin from saidconstruction.

2. A construction in accordance with claim 1 wherein said pull out pinengages an intermediate portion of said wire contact, said terminalelements extending through said support member with the respective endportions of said wire contact being normally urged into engagement withsaid terminal elements.

3. A construction in accordance with claim 1 compris-v ing an enlargedinterior portion, and including a disturb switch confined within saidinterior portion, said disturb switch including terminal members xed incontacting position with other terminals of said switch construction,and means for makingV contact between the terminal members of saiddisturb switch when said switch construction is subjected to outsidephysical forces.

4. A disturb switch comprising a coil spring defining an open interior,means supporting said spring at its opposite ends, a conductive walllocated in spaced-apart surrounding relationship relative to theexterior surface of said spring, said supporting means comprising afirst electrical terminal contacting said spring, a second terminalconnected to said conductive wall, means whereby a portion of saidspring intermediate said supported ends is maintained in a position ofrest out of contact with said conductive wall, a weight located wthinsaid spring, means whereby said Weight moves said intermediate portionof the spring into direct contact with said conductive wall when saidswitch is subjected to outside physical forces.

5. A switch in accordance with claim 4 wherein said weight comprises ametal ball freely movable within the interior of said spring.

References Cited UNITED STATES PATENTS 867,743 10/1907 'Murdock 20G-51.11,719,742 7/ 1929 Adams 200%52 2,561,342 7/1951 Collins et al. 200-6l.45XR 2,835,759 5/1958 Waldow 20G-61.45 XR 1,057,1879 4/ 1913 Quain 200-1663,457,431 7/1969 Zingg et al. IGZ-70.2 XR

IROBERT K. SCHAEFER, iPrimary Examiner M. GINSBURG, Assistant ExaminerlUs. C1. XJR, 20G-61.59; 102-70.2

